So the homeowner would have been killed instead of the burglars?
I don't exactly know why/how. But here in the UK, we have very few guns and yet usually feel safe in our homes. Partly it is because we usually have fast responding (where necessary) and well equipped Police forces, crime rates are reasonably low and home invasions are usually very rare and (mostly) non-violent.
But I'm not exactly sure why there are these differences between the UK and the US.
But before someone jumps in to disagree. I agree that at times the UK also has bad/serious crimes including violent home invasions.
The problem (in my view) seems to be that allowing lots of guns into society, as well as helping defend householders, like in this case. Actually causes/allows many other gun related deaths, including mass shootings and worse terrorist acts, than if they had not had easy access to guns.
Shrug, a pump action shotgun with 00 buckshot would have made them just as dead but made way more of a mess.
I thought a similar thing, even before your post. I agree, it would probably have had a similar outcome.
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tl;dr
Although gun(s) helped in this case, I worry about all the other gun incidents where innocent lives were taken.